This enhancement request is based on the following forum-thread where a lot of well respected community members have contributed. http://forums.slimdevices.com/showthread.php?t=75381

The user interface in relation to managing the setup of synchronization is really not very good.
If you want to sync more than two players you need to switch between the players in order both to set it up and to stop the sync again. 
Even with just two players, the occasional sync-user will find them wiping their playlist about 50% of the time because they forget which way the playlist is moved.

This is one of the major drawbacks compared to the main competitor, Sonos. In any comparison as a whole-house audio system, Logitech gets bashed for the lack of intuitive sync-UI.

There are 3rd party plugins available that to some extent can remedy the lack in the core functionality.  (Other Players and The Synchronizer) But I think this is a vital part of the Squeezebox UI which should not be left to 3rd parties to get right.

It should be possible to enable and disable sync of multiple players without having to switch between the players.

This can be achieved in a number of ways.  
One of them could be a wizard.
1st step: List all “visible” players (from all local servers and MySB.com). Checkbox the players you want in the sync-group. 
2nd step. Radio button choice of which player’s playlist should be adapted. (Default choice is the player you are currently controlling)
3rd step. Choice whether to save sync-group or if it’s for one-time-use.
4th step. Assign name to group if chosen to save.

When the sync-menu is opened I imagine it to look something like this:
1. Start previously saved sync group a
2. Start previously saved sync group b
3. Create new synchronization  group
4. Stop Synchronization – which pulls up a dialog for choosing which sync to stop. Perhaps a wizard so single players can be pulled out of a sync-group.

This is just one way to do it. Other ideas can be found in the forum-thread.

This way to do it of course mostly benefits users with more than two players, but even with just two players it will be an improvement, since you can both push and pull the playlist to/from the player you are currently controlling. And there is no confusion about which playlist is adapted.

http://forums.slimdevices.com/showthread.php?t=75381